Data storage devices employ actuators to position data storing and retrieving heads with extremely abrupt accelerations and high velocities. Storage densities have dramatically increased while access times have dramatically decreased, the impact of which being that consideration of actuator resonant performance has become increasingly more important in designing for reliable data transfer.
The actuator has a flexible suspension portion involving a load beam imparting a biasing force on the head in opposition to the fluid bearing pushing the head away from the data medium. The load beam includes a preload bend section that gives the load beam a desired vertical stiffness, and around which the head articulates as the fly height varies such as during head loading and unloading. Accordingly, the vertical stiffness must be within a range permitting reliable articulation and fly performance. However, the vertical stiffness cannot be achieved at the cost of reducing resonant performance, resulting in reduced track following performance.
Particularly, reducing the material bend strength of the bend section aids in reducing the vertical stiffness, but disadvantageously also reduces the sway stiffness and torsional stiffness, resulting in resonant frequency disturbances. What is needed is a solution that employs a bend section made from a thickness that is optimized for the sway and torsional stiffness, but which is modified to likewise optimize the vertical stiffness without adversely affecting the desired sway and torsional stiffness. It is to these improvement features that the embodiments of the present invention are directed.